Cervical Vertebrae
Age Determination by Skeleton
Klippel-Feil Syndrome
Axis
Thoracic Vertebrae
Greek World
Byzantium
Lumbar Vertebrae
Catarrhini
Musculoskeletal Abnormalities
Carpal Bones
Spinal Diseases
Alouatta
Hand Bones
Atelinae
Dinosaurs
X-Ray Intensifying Screens
Vertebral Artery
Intervertebral Disc
Spinal Neoplasms
Internal Fixators
Bone Development
Odontoid Process
Scapula
Spinal Fusion
Malocclusion
Tomography, X-Ray Computed
Genes, Homeobox
Bone and Bones
Dog Diseases
Scoliosis
Homeodomain Proteins
Sacrum
Vertebroplasty
Ribs
Fractures, Compression
Magnetic Resonance Imaging
Spondylolysis
Kyphosis
Polymethyl Methacrylate
Sex Factors
Spinal Curvatures
Tail
Weight-Bearing
Biomechanical Phenomena
Bone Cements
Orthopedic Fixation Devices
Kyphoplasty
Compressive Strength
Bone Density
Tuberculosis, Spinal
Wasting of the small hand muscles in upper and mid-cervical cord lesions. (1/2270)
Four patients are described with destructive rheumatoid arthritis of the cervical spine and neurogenic wasting of forearm and hand muscles. The pathological connection is not immediately obvious, but a relationship between these two observations is described here with clinical, radiological, electrophysiological and necropsy findings. Compression of the anterior spinal artery at upper and mid-cervical levels is demonstrated to be the likely cause of changes lower in the spinal cord. These are shown to be due to the resulting ischaemia of the anterior part of the lower cervical spinal cord, with degeneration of the neurones innervating the forearm and hand muscles. These findings favour external compression of the anterior spinal artery leading to ischaemia in a watershed area as the likeliest explanation for this otherwise inappropriate and bizarre phenomenon. (+info)Genetic influences on cervical and lumbar disc degeneration: a magnetic resonance imaging study in twins. (2/2270)
OBJECTIVE: Degenerative intervertebral disc disease is common; however, the importance of genetic factors is unknown. This study sought to determine the extent of genetic influences on disc degeneration by classic twin study methods using magnetic resonance imaging (MRI). METHODS: We compared MRI features of degenerative disc disease in the cervical and lumbar spine of 172 monozygotic and 154 dizygotic twins (mean age 51.7 and 54.4, respectively) who were unselected for back pain or disc disease. An overall score for disc degeneration was calculated as the sum of the grades for disc height, bulge, osteophytosis, and signal intensity at each level. A "severe disease" score (excluding minor grades) and an "extent of disease" score (number of levels affected) were also calculated. RESULTS: For the overall score, heritability was 74% (95% confidence interval [95% CI] 64-81%) at the lumbar spine and 73% (95% CI 64-80%) at the cervical spine. For "severe disease," heritability was 64% and 79% at the lumbar and cervical spine, respectively, and for "extent of disease," heritability was 63% and 63%, respectively. These results were adjusted for age, weight, height, smoking, occupational manual work, and exercise. Examination of individual features revealed that disc height and bulge were highly heritable at both sites, and osteophytes were heritable in the lumbar spine. CONCLUSION: These results suggest an important genetic influence on variation in intervertebral disc degeneration. However, variation in disc signal is largely influenced by environmental factors shared by twins. The use of MRI scans to determine the phenotype in family and population studies should allow a better understanding of disease mechanisms and the identification of the genes involved. (+info)Disabling injuries of the cervical spine in Argentine rugby over the last 20 years. (3/2270)
OBJECTIVE: To investigate the incidence and risk factors of disabling injuries to the cervical spine in rugby in Argentina. METHODS: A retrospective review of all cases reported to the Medical Committee of the Argentine Rugby Union (UAR) and Rugby Amistad Foundation was carried out including a follow up by phone. Cumulative binomial distribution, chi 2 test, Fisher test, and comparison of proportions were used to analyse relative incidence and risk of injury by position and by phase of play (Epi Info 6, Version 6.04a). RESULTS: Eighteen cases of disabling injury to the cervical spine were recorded from 1977 to 1997 (0.9 cases per year). The forwards (14 cases) were more prone to disabling injury of the cervical spine than the backs (four cases) (p = 0.03). Hookers (9/18) were at highest risk of injury (p < 0.01). The most frequent cervical injuries occurred at the 4th, 5th, and 6th vertebrae. Seventeen of the injuries occurred during match play. Set scrums were responsible for most of the injuries (11/18) but this was not statistically significant (p = 0.44). The mean age of the injured players was 22. Tetraplegia was initially found in all cases. Physical rehabilitation has been limited to the proximal muscles of the upper limbs, except for two cases of complete recovery. One death, on the seventh day after injury, was reported. CONCLUSIONS: The forwards suffered a higher number of injuries than the backs and this difference was statistically significant. The chance of injury for hookers was statistically higher than for the rest of the players and it was particularly linked to scrummaging. However, the number of injuries incurred in scrums was not statistically different from the number incurred in other phases of play. (+info)Cluster headache-like attack as an opening symptom of a unilateral infarction of the cervical cord: persistent anaesthesia and dysaesthesia to cold stimuli. (4/2270)
A 54 year old man experienced excruciating left retro-orbital pain with lacrimation and redness of the eye representative of a cluster headache attack. This was followed by left hemiparesis with plegia of the lower limb and left Horner's syndrome. Five days later the hemiparesis recovered while the patient developed hypoanaesthesia to cold stimuli that evoked painful burning dysaesthesia on the right side below the C4 level. MRI disclosed a discrete infarct in the left lateral aspect of the cord at C2 level concomitant to a left vertebral artery thrombosis. This limited infarct and the clinical symptoms suggest a hypoperfusion in the peripheral arterial system of the left hemicord, supplied both by the anterior and posterior spinal arteries. Cluster headache-like attack and persistent dysaesthesia to cold stimuli are discussed respectively in view of the central sympathetic involvement and partial spinothalamic system dysfunction. (+info)Bilateral vertebral artery occlusion following cervical spine trauma--case report. (5/2270)
A 41-year-old female presented with a rare case of bilateral vertebral artery occlusion following C5-6 cervical spine subluxation after a fall of 30 feet. Digital subtraction angiography showed occlusion of the bilateral vertebral arteries. Unlocking of the facet joint, posterior wiring with iliac crest grafting, and anterior fusion were performed. The patient died on the 3rd day after the operation. This type of injury has a grim prognosis with less than a third of the patients achieving a good outcome. (+info)In vivo and in vitro CT analysis of the occiput. (6/2270)
Arguments concerning the best procedure for occipito-cervical fusion have rarely been based upon occipital bone thickness or only based on in vitro studies. To close this gap and to offer an outlook on preoperative evaluation of the patient, 28 patients were analysed in vivo by means of spiral CT. Ten macerated human skulls were measured by means of CT and directly. Measurements were taken according to a matrix of 66 points following a grid with 1 cm spacing based upon McRae's line. Maximum thickness in the patient group was met 4 cm above the reference plane in the median slice (11.87 mm; SD 3.41 mm) and 5 cm above it in the skull group (15.85 mm; SD 1.81 mm). Correlation between CT and direct measurements was good (91.79%). Intra-individual discrepancies from one side to the respective point on the other side are common (difference > 1 mm in 60%). Judging areas suitable for operative fixation using the 10% percentile value (6.68 mm for the maximum value of 11.87 mm) led to the conclusion that screws should only be inserted along the occipital crest in an area extending from 1.5 cm above the posterior margin of the foramen magnum to the external occipital protuberance (EOP). At the level of the EOP screws may also be inserted up to 1 cm lateral of the midline. A reduction of screw length to 7 mm (9 mm for the EOP) is proposed. Preoperative evaluation of the patient should be carried out by spiral CT with 1 mm slicing and sagittal reconstructions. (+info)A clinico-pathological study of cervical myelopathy in rheumatoid arthritis: post-mortem analysis of two cases. (7/2270)
Two patients who developed cervical myelopathy secondary to rheumatoid arthritis were analyzed post mortem. One patient had anterior atlanto-axial subluxation (AAS) combined with subaxial subluxation (SS), and the other had vertical subluxation (VS) combined with SS. In the patient with AAS, the posterior aspect of the spinal cord demonstrated severe constriction at the C2 segment, which arose from dynamic osseous compression by the C1 posterior arch. A histological cross-section of the spinal cord at the segment was characterized by distinct necrosis in the posterior white columns and the gray matter. In the patient with VS, the upper cervical cord and medulla oblongata showed angulation over the invaginated odontoid process, whereas no significant pathological changes were observed. At the level of SS, the spinal cord was pinched and compressed between the upper corner of the vertebral body and the lower edge of the lamina. Histologically, demyelination and gliosis were observed in the posterior and lateral white columns. (+info)Hypoglossal nerve injury as a complication of anterior surgery to the upper cervical spine. (8/2270)
Injury to the hypoglossal nerve is a recognised complication after soft tissue surgery in the upper part of the anterior aspect of the neck, e.g. branchial cyst or carotid body tumour excision. However, this complication has been rarely reported following surgery of the upper cervical spine. We report the case of a 35-year-old woman with tuberculosis of C2-3. She underwent corpectomy and fusion from C2 to C5 using iliac crest bone graft, through a left anterior oblique incision. She developed hypoglossal nerve palsy in the immediate postoperative period, with dysphagia and dysarthria. It was thought to be due to traction neurapraxia with possible spontaneous recovery. At 18 months' follow-up, she had a solid fusion and tuberculosis was controlled. The hypoglossal palsy persisted, although with minimal functional disability. The only other reported case of hypoglossal lesion after anterior cervical spine surgery in the literature also failed to recover. It is concluded that hypoglossal nerve palsy following anterior cervical spine surgery is unlikely to recover spontaneously and it should be carefully identified. (+info)The cervical vertebrae are the seven vertebrae that make up the upper part of the spine, also known as the neck region. They are labeled C1 to C7, with C1 being closest to the skull and C7 connecting to the thoracic vertebrae in the chest region. The cervical vertebrae have unique structures to allow for a wide range of motion in the neck while also protecting the spinal cord and providing attachment points for muscles and ligaments.
The Cervical Atlas, also known as C1 or the atlas vertebra, is the uppermost and most superior of the seven cervical vertebrae in the human spine. It plays a crucial role in supporting and facilitating the movement of the head, as it articulates with both the occipital bone (forming the joint called the atlanto-occipital joint) and the axis (or C2) vertebra (forming the atlantoaxial joint). The unique structure of the cervical atlas lacks a body, instead having an anterior and posterior arch with two lateral masses that form the facet joints for articulation with the axis. This arrangement allows for a wide range of motion in the neck, including flexion, extension, lateral bending, and rotation.
Age determination by skeleton, also known as skeletal aging or skeletal maturation, is the process of estimating a person's age based on the analysis of their skeletal remains. This technique is commonly used in forensic anthropology to help identify unknown individuals or determine the time since death.
The method involves examining various features of the skeleton, such as the degree of fusion of epiphyseal growth plates, the shape and size of certain bones, and the presence or absence of degenerative changes. These features change in a predictable way as a person grows and develops, allowing for an estimation of their age at death.
It is important to note that while skeletal aging can provide useful information, it is not always possible to determine an exact age. Instead, forensic anthropologists typically provide a range of ages that the individual may have fallen into based on the skeletal evidence. Additionally, factors such as genetics, nutrition, and health can affect the rate at which skeletal features develop, making it difficult to provide a precise estimate in some cases.
Klippel-Feil Syndrome is a rare congenital condition characterized by the abnormal fusion or joining of two or more spinal bones (vertebrae) in the neck (cervical region). This fusion typically occurs during fetal development and can affect one or more levels of the cervical spine. The syndrome is usually diagnosed in early childhood, although milder cases may not be detected until later in life.
The medical definition of Klippel-Feil Syndrome includes the following major features:
1. Congenital fusion (synostosis) of two or more cervical vertebrae: This fusion can result in restricted mobility and increased stiffness in the neck, which may lead to a decreased range of motion and potential complications such as spinal cord injuries.
2. Short neck: A shortened neck is often observed in individuals with Klippel-Feil Syndrome due to the fusion of vertebrae. This feature can be associated with a low hairline at the back of the head (occipital low hairline) and limited mobility in the upper spine.
3. Webbed neck: Some individuals with Klippel-Feil Syndrome may have a webbed or wide neck, which is characterized by excess skin and soft tissue in the neck region. This feature can be mild or severe and may impact the overall appearance of the individual.
In addition to these primary features, Klippel-Feil Syndrome can also be associated with several secondary symptoms and conditions, including:
1. Spinal deformities: Scoliosis (lateral curvature of the spine) or kyphosis (excessive forward curvature of the spine) may occur due to the abnormal spinal development.
2. Neurological complications: Compression or irritation of the spinal cord or nerves can lead to various neurological symptoms, such as numbness, tingling, or weakness in the arms and legs.
3. Genitourinary anomalies: Approximately 30% of individuals with Klippel-Feil Syndrome have genitourinary abnormalities, including kidney malformations, horseshoe kidney, or abnormalities in the reproductive organs.
4. Hearing impairment: Up to 50% of individuals with Klippel-Feil Syndrome may experience hearing loss or other auditory issues due to inner ear anomalies.
5. Craniofacial abnormalities: Some individuals with Klippel-Feil Syndrome may have craniofacial abnormalities, such as cleft palate, low-set ears, or a small jaw (micrognathia).
6. Cardiovascular anomalies: Approximately 10% of individuals with Klippel-Feil Syndrome have cardiovascular abnormalities, including heart defects or blood vessel malformations.
The exact cause of Klippel-Feil Syndrome is not fully understood, but it is believed to result from abnormal development of the cervical vertebrae during embryonic growth. In some cases, it may be associated with genetic mutations or chromosomal abnormalities; however, in many instances, no specific cause can be identified.
Diagnosis of Klippel-Feil Syndrome typically involves a combination of physical examination and imaging studies, such as X-rays, CT scans, or MRI exams. These tests help to assess the structure and alignment of the cervical spine and identify any associated abnormalities.
Treatment for Klippel-Feil Syndrome depends on the severity of symptoms and the presence of any complications. In some cases, no specific treatment may be necessary beyond regular monitoring by a healthcare provider. However, if neck pain, limited mobility, or other issues are present, various therapies and interventions may be recommended, including:
1. Physical therapy: Exercises and stretches can help improve strength, flexibility, and range of motion in the neck and surrounding muscles.
2. Pain management: Medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) or opioids, may be prescribed to help alleviate pain and discomfort. In some cases, injections of corticosteroids or other medications may be used to target specific areas of inflammation or pain.
3. Surgery: If severe deformities, instability, or neurological complications are present, surgery may be necessary to stabilize the spine and prevent further damage. Various surgical techniques, such as spinal fusion or decompression procedures, may be used depending on the specific needs of the patient.
4. Lifestyle modifications: Avoiding activities that exacerbate symptoms, maintaining good posture, and using supportive devices, such as neck braces or pillows, can help manage symptoms and prevent further injury.
5. Regular follow-up care: Regular checkups with a healthcare provider are essential to monitor the progression of Klippel-Feil Syndrome and address any new or worsening symptoms as they arise.
In medical terms, "axis" is used to describe a line or lines along which a structure or body part can move or around which it is oriented. It is often used in anatomical context to refer to specific axes of movement or alignment for various parts of the body. For example:
* The axial skeleton, also known as the upright skeleton, includes the skull, vertebral column, and chest cage.
* In neurology, the term "axis" is used to describe the second cervical vertebra (C2), which is also called the axis because it serves as a pivot point for head movement.
* The term "longitudinal axis" is used to describe an imaginary line that runs from the head to the foot, passing through the center of the body.
* In imaging studies such as X-rays or MRIs, the term "axis" may be used to describe a specific orientation or alignment for the image.
Overall, the term "axis" is used in medicine to describe lines or planes that serve as reference points for movement, alignment, or orientation of various body structures and parts.
The thoracic vertebrae are the 12 vertebrae in the thoracic region of the spine, which is the portion between the cervical and lumbar regions. These vertebrae are numbered T1 to T12, with T1 being closest to the skull and T12 connecting to the lumbar region.
The main function of the thoracic vertebrae is to provide stability and support for the chest region, including protection for the vital organs within, such as the heart and lungs. Each thoracic vertebra has costal facets on its sides, which articulate with the heads of the ribs, forming the costovertebral joints. This connection between the spine and the ribcage allows for a range of movements while maintaining stability.
The thoracic vertebrae have a unique structure compared to other regions of the spine. They are characterized by having long, narrow bodies, small bony processes, and prominent spinous processes that point downwards. This particular shape and orientation of the thoracic vertebrae contribute to their role in limiting excessive spinal movement and providing overall trunk stability.
I believe there may be some confusion in your question as "Greek World" is not a medical term. If you are referring to the ancient Greek civilization, it was a significant period in human history that greatly contributed to the development of various fields including medicine. The ancient Greeks, particularly Hippocrates and his followers, are often referred to as the "Fathers of Medicine." They made substantial contributions to the field through their observations, theories, and practices which formed the foundation of much of Western medical thought. However, "Greek World" itself does not have a medical definition.
"Byzantium" is a historical term that refers to the city of Constantinople, which is now known as Istanbul in modern-day Turkey. The term is most commonly used in reference to the Byzantine Empire, also known as the Eastern Roman Empire, which was a continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages.
The Byzantine Empire had its capital at Constantinople, which was founded by the Roman Emperor Constantine the Great in 324 AD and was renamed after him as "Constantinopolis" or "Constantinople." The term "Byzantium" is derived from the name of the earlier Greek colony that existed on the site of Constantinople, known as "Byzantion."
There is no medical definition associated with the term "Byzantium," as it is a historical and geographical term.
The spine, also known as the vertebral column, is a complex structure in the human body that is part of the axial skeleton. It is composed of 33 individual vertebrae (except in some people where there are fewer due to fusion of certain vertebrae), intervertebral discs, facet joints, ligaments, muscles, and nerves.
The spine has several important functions:
1. Protection: The spine protects the spinal cord, which is a major component of the nervous system, by enclosing it within a bony canal.
2. Support: The spine supports the head and upper body, allowing us to maintain an upright posture and facilitating movement of the trunk and head.
3. Movement: The spine enables various movements such as flexion (bending forward), extension (bending backward), lateral flexion (bending sideways), and rotation (twisting).
4. Weight-bearing: The spine helps distribute weight and pressure evenly across the body, reducing stress on individual vertebrae and other structures.
5. Blood vessel and nerve protection: The spine protects vital blood vessels and nerves that pass through it, including the aorta, vena cava, and spinal nerves.
The spine is divided into five regions: cervical (7 vertebrae), thoracic (12 vertebrae), lumbar (5 vertebrae), sacrum (5 fused vertebrae), and coccyx (4 fused vertebrae, also known as the tailbone). Each region has unique characteristics that allow for specific functions and adaptations to the body's needs.
The lumbar vertebrae are the five largest and strongest vertebrae in the human spine, located in the lower back region. They are responsible for bearing most of the body's weight and providing stability during movement. The lumbar vertebrae have a characteristic shape, with a large body in the front, which serves as the main weight-bearing structure, and a bony ring in the back, formed by the pedicles, laminae, and processes. This ring encloses and protects the spinal cord and nerves. The lumbar vertebrae are numbered L1 to L5, starting from the uppermost one. They allow for flexion, extension, lateral bending, and rotation movements of the trunk.
Cephalometry is a medical term that refers to the measurement and analysis of the skull, particularly the head face relations. It is commonly used in orthodontics and maxillofacial surgery to assess and plan treatment for abnormalities related to the teeth, jaws, and facial structures. The process typically involves taking X-ray images called cephalograms, which provide a lateral view of the head, and then using various landmarks and reference lines to make measurements and evaluate skeletal and dental relationships. This information can help clinicians diagnose problems, plan treatment, and assess treatment outcomes.
Catarrhini is a taxonomic group within the order Primates, which includes Old World monkeys, apes, and humans. This group is defined by several distinct anatomical features, most notably the presence of a specific type of nose and throat structure that results in a downward-facing nostril and a narrow nasopharynx.
The term "catarrhine" comes from the Greek words "kata," meaning "downwards," and "rhis," meaning "nose." This refers to the distinctive shape of the nose and throat, which is different from that of New World monkeys (Platyrrhini), which have a wider nasopharynx and outward-facing nostrils.
Other features that distinguish Catarrhini from other primates include a more complex brain, a greater reliance on color vision, and a more varied diet that includes both plants and animals. Within the Catarrhini group, there are two main subgroups: Cercopithecoidea (Old World monkeys) and Hominoidea (apes and humans).
Overall, the medical definition of "Catarrhini" refers to a specific taxonomic group within the order Primates that includes Old World monkeys, apes, and humans, and is characterized by distinct anatomical features such as downward-facing nostrils and a narrow nasopharynx.
Musculoskeletal abnormalities refer to structural and functional disorders that affect the musculoskeletal system, which includes the bones, muscles, cartilages, tendons, ligaments, joints, and other related tissues. These abnormalities can result from genetic factors, trauma, overuse, degenerative processes, infections, or tumors. They may cause pain, stiffness, limited mobility, deformity, weakness, and susceptibility to injuries. Examples of musculoskeletal abnormalities include osteoarthritis, rheumatoid arthritis, scoliosis, kyphosis, lordosis, fractures, dislocations, tendinitis, bursitis, myopathies, and various congenital conditions.
Carpal bones are the eight small bones that make up the wrist joint in humans and other primates. These bones are arranged in two rows, with four bones in each row. The proximal row includes the scaphoid, lunate, triquetral, and pisiform bones, while the distal row includes the trapezium, trapezoid, capitate, and hamate bones.
The carpal bones play an essential role in the function of the wrist joint by providing stability, support, and mobility. They allow for a wide range of movements, including flexion, extension, radial deviation, ulnar deviation, and circumduction. The complex structure of the carpal bones also helps to absorb shock and distribute forces evenly across the wrist during activities such as gripping or lifting objects.
Injuries to the carpal bones, such as fractures or dislocations, can be painful and may require medical treatment to ensure proper healing and prevent long-term complications. Additionally, degenerative conditions such as arthritis can affect the carpal bones, leading to pain, stiffness, and decreased mobility in the wrist joint.
Spinal diseases refer to a range of medical conditions that affect the spinal column, which is made up of vertebrae (bones), intervertebral discs, facet joints, nerves, ligaments, and muscles. These diseases can cause pain, discomfort, stiffness, numbness, weakness, or even paralysis, depending on the severity and location of the condition. Here are some examples of spinal diseases:
1. Degenerative disc disease: This is a condition where the intervertebral discs lose their elasticity and height, leading to stiffness, pain, and decreased mobility.
2. Herniated disc: This occurs when the inner material of the intervertebral disc bulges or herniates out through a tear in the outer layer, causing pressure on the spinal nerves and resulting in pain, numbness, tingling, or weakness in the affected area.
3. Spinal stenosis: This is a narrowing of the spinal canal or the neural foramen (the openings where the spinal nerves exit the spinal column), which can cause pressure on the spinal cord or nerves and result in pain, numbness, tingling, or weakness.
4. Scoliosis: This is a curvature of the spine that can occur in children or adults, leading to an abnormal posture, back pain, and decreased lung function.
5. Osteoarthritis: This is a degenerative joint disease that affects the facet joints in the spine, causing pain, stiffness, and decreased mobility.
6. Ankylosing spondylitis: This is a chronic inflammatory disease that affects the spine and sacroiliac joints, leading to pain, stiffness, and fusion of the vertebrae.
7. Spinal tumors: These are abnormal growths that can occur in the spinal column, which can be benign or malignant, causing pain, neurological symptoms, or even paralysis.
8. Infections: Bacterial or viral infections can affect the spine, leading to pain, fever, and other systemic symptoms.
9. Trauma: Fractures, dislocations, or sprains of the spine can occur due to accidents, falls, or sports injuries, causing pain, neurological deficits, or even paralysis.
"Alouatta" is a genus of species that are commonly known as howler monkeys. They are native to the forests of Central and South America. These monkeys are recognized for their loud howls, which can be heard miles away in the forest. The howls are used to communicate with other members of their group and establish territory. Howler monkeys have a strong grip and spend most of their time in the trees. They are primarily herbivores, eating mostly leaves, fruits, and buds.
The term "hand bones" refers to the skeletal components that make up the human hand. These bones are divided into three categories: carpals, metacarpals, and phalanges.
1. Carpals: There are eight carpal bones arranged in two rows in the wrist region. The proximal row consists of the scaphoid, lunate, triquetral, and pisiform bones, while the distal row includes the trapezium, trapezoid, capitate, and hamate bones.
2. Metacarpals: There are five metacarpal bones, one for each finger, located in the middle part of the hand between the carpals and phalanges. They are numbered 1 to 5 from the thumb side to the little finger side.
3. Phalanges: These are the bones found in the fingers and thumb. Each finger has three phalanges (proximal, middle, and distal), while the thumb only has two (proximal and distal). In total, there are 14 phalangeal bones in the hand.
Together, these hand bones provide structure, support, and mobility to the hand, enabling various complex movements essential for daily activities.
'Atelinae' is a biological classification category, specifically a tribe, that includes several genera of New World monkeys. These monkeys are characterized by their lack of a tail-grasping reflex and the presence of ischial callosities, which are thickened areas of skin on their buttocks that they use for sitting.
The tribe Atelinae includes the following genera:
* Ateles (spider monkeys)
* Brachyteles (muriquis or woolly spider monkeys)
* Lagothrix (woolly monkeys)
* Oreonax (the yellow-tailed woolly monkey)
These monkeys are native to Central and South America, where they inhabit a variety of forest habitats. They are generally arboreal, spending most of their time in trees, and have a varied diet that includes fruits, leaves, flowers, and insects. Many species of Atelinae are endangered due to habitat loss and hunting.
Dinosaurs are a group of reptiles that were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous period. They first appeared approximately 230 million years ago and went extinct around 65 million years ago.
Dinosaurs are characterized by their upright stance, with legs positioned directly under their bodies, and a wide range of body sizes and shapes. Some dinosaurs were enormous, such as the long-necked sauropods that could reach lengths of over 100 feet, while others were small and agile.
Dinosaurs are classified into two main groups: the saurischians (lizard-hipped) and the ornithischians (bird-hipped). The saurischians include both the large carnivorous theropods, such as Tyrannosaurus rex, and the long-necked sauropods. The ornithischians were primarily herbivores and included a diverse array of species, such as the armored ankylosaurs and the horned ceratopsians.
Despite their extinction, dinosaurs have left a lasting impact on our planet and continue to be a source of fascination for people of all ages. The study of dinosaurs, known as paleontology, has shed light on many aspects of Earth's history and the evolution of life on our planet.
X-ray intensifying screens are medical imaging devices that contain phosphorescent materials, which emit light in response to the absorption of X-ray radiation. They are used in conjunction with X-ray film to enhance the visualization of radiographic images by converting X-rays into visible light. The screens are placed inside a cassette, along with the X-ray film, and exposed to X-rays during medical imaging procedures such as radiography or fluoroscopy.
The phosphorescent materials in the intensifying screens absorb most of the X-ray energy and re-emit it as visible light, which then exposes the X-ray film. This process increases the efficiency of the X-ray exposure, reducing the amount of radiation required to produce a diagnostic image. The use of intensifying screens can significantly improve the quality and detail of radiographic images while minimizing patient exposure to ionizing radiation.
The vertebral artery is a major blood vessel that supplies oxygenated blood to the brain and upper spinal cord. It arises from the subclavian artery, then ascends through the transverse processes of several cervical vertebrae before entering the skull through the foramen magnum. Inside the skull, it joins with the opposite vertebral artery to form the basilar artery, which supplies blood to the brainstem and cerebellum. The vertebral artery also gives off several important branches that supply blood to various regions of the brainstem and upper spinal cord.
An intervertebral disc is a fibrocartilaginous structure found between the vertebrae of the spinal column in humans and other animals. It functions as a shock absorber, distributes mechanical stress during weight-bearing activities, and allows for varying degrees of mobility between adjacent vertebrae.
The disc is composed of two parts: the annulus fibrosus, which forms the tough, outer layer; and the nucleus pulposus, which is a gel-like substance in the center that contains proteoglycans and water. The combination of these components provides the disc with its unique ability to distribute forces and allow for movement.
The intervertebral discs are essential for the normal functioning of the spine, providing stability, flexibility, and protection to the spinal cord and nerves. However, they can also be subject to degeneration and injury, which may result in conditions such as herniated discs or degenerative disc disease.
Bone screws are medical devices used in orthopedic and trauma surgery to affix bone fracture fragments or to attach bones to other bones or to metal implants such as plates, rods, or artificial joints. They are typically made of stainless steel or titanium alloys and have a threaded shaft that allows for purchase in the bone when tightened. The head of the screw may have a hexagonal or star-shaped design to allow for precise tightening with a screwdriver. Bone screws come in various shapes, sizes, and designs, including fully threaded, partially threaded, cannulated (hollow), and headless types, depending on their intended use and location in the body.
Spinal neoplasms refer to abnormal growths or tumors found within the spinal column, which can be benign (non-cancerous) or malignant (cancerous). These tumors can originate in the spine itself, called primary spinal neoplasms, or they can spread to the spine from other parts of the body, known as secondary or metastatic spinal neoplasms. Spinal neoplasms can cause various symptoms, such as back pain, neurological deficits, and even paralysis, depending on their location and size. Early diagnosis and treatment are crucial to prevent or minimize long-term complications and improve the patient's prognosis.
Internal fixators are medical devices that are implanted into the body through surgery to stabilize and hold broken or fractured bones in the correct position while they heal. These devices can be made from various materials, such as metal (stainless steel or titanium) or bioabsorbable materials. Internal fixators can take many forms, including plates, screws, rods, nails, wires, or cages, depending on the type and location of the fracture.
The main goal of using internal fixators is to promote bone healing by maintaining accurate reduction and alignment of the fractured bones, allowing for early mobilization and rehabilitation. This can help reduce the risk of complications such as malunion, nonunion, or deformity. Internal fixators are typically removed once the bone has healed, although some bioabsorbable devices may not require a second surgery for removal.
It is important to note that while internal fixators provide stability and support for fractured bones, they do not replace the need for proper immobilization, protection, or rehabilitation during the healing process. Close follow-up with an orthopedic surgeon is essential to ensure appropriate healing and address any potential complications.
Bone development, also known as ossification, is the process by which bone tissue is formed and grows. This complex process involves several different types of cells, including osteoblasts, which produce new bone matrix, and osteoclasts, which break down and resorb existing bone tissue.
There are two main types of bone development: intramembranous and endochondral ossification. Intramembranous ossification occurs when bone tissue forms directly from connective tissue, while endochondral ossification involves the formation of a cartilage model that is later replaced by bone.
During fetal development, most bones develop through endochondral ossification, starting as a cartilage template that is gradually replaced by bone tissue. However, some bones, such as those in the skull and clavicles, develop through intramembranous ossification.
Bone development continues after birth, with new bone tissue being laid down and existing tissue being remodeled throughout life. This ongoing process helps to maintain the strength and integrity of the skeleton, allowing it to adapt to changing mechanical forces and repair any damage that may occur.
The odontoid process, also known as the dens, is a tooth-like projection from the second cervical vertebra (axis). It fits into a ring formed by the first vertebra (atlas), allowing for movement between these two vertebrae. The odontoid process helps to support the head and facilitates movements such as nodding and shaking. It is an essential structure in maintaining stability and mobility of the upper spine.
The scapula, also known as the shoulder blade, is a flat, triangular bone located in the upper back region of the human body. It serves as the site of attachment for various muscles that are involved in movements of the shoulder joint and arm. The scapula has several important features:
1. Three borders (anterior, lateral, and medial)
2. Three angles (superior, inferior, and lateral)
3. Spine of the scapula - a long, horizontal ridge that divides the scapula into two parts: supraspinous fossa (above the spine) and infraspinous fossa (below the spine)
4. Glenoid cavity - a shallow, concave surface on the lateral border that articulates with the humerus to form the shoulder joint
5. Acromion process - a bony projection at the top of the scapula that forms part of the shoulder joint and serves as an attachment point for muscles and ligaments
6. Coracoid process - a hook-like bony projection extending from the anterior border, which provides attachment for muscles and ligaments
Understanding the anatomy and function of the scapula is essential in diagnosing and treating various shoulder and upper back conditions.
Spinal fusion is a surgical procedure where two or more vertebrae in the spine are fused together to create a solid bone. The purpose of this procedure is to restrict movement between the fused vertebrae, which can help reduce pain and stabilize the spine. This is typically done using bone grafts or bone graft substitutes, along with hardware such as rods, screws, or cages to hold the vertebrae in place while they heal together. The procedure may be recommended for various spinal conditions, including degenerative disc disease, spinal stenosis, spondylolisthesis, scoliosis, or fractures.
Malocclusion is a term used in dentistry and orthodontics to describe a misalignment or misrelation between the upper and lower teeth when they come together, also known as the bite. It is derived from the Latin words "mal" meaning bad or wrong, and "occludere" meaning to close.
There are different types of malocclusions, including:
1. Class I malocclusion: The most common type, where the upper teeth slightly overlap the lower teeth, but the bite is otherwise aligned.
2. Class II malocclusion (overbite): The upper teeth significantly overlap the lower teeth, causing a horizontal or vertical discrepancy between the dental arches.
3. Class III malocclusion (underbite): The lower teeth protrude beyond the upper teeth, resulting in a crossbite or underbite.
Malocclusions can be caused by various factors such as genetics, thumb sucking, tongue thrusting, premature loss of primary or permanent teeth, and jaw injuries or disorders. They may lead to several oral health issues, including tooth decay, gum disease, difficulty chewing or speaking, and temporomandibular joint (TMJ) dysfunction. Treatment for malocclusions typically involves orthodontic appliances like braces, aligners, or retainers to realign the teeth and correct the bite. In some cases, surgical intervention may be necessary.
X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.
The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.
CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.
In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.
CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.
In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.
In medical terms, the "neck" is defined as the portion of the body that extends from the skull/head to the thorax or chest region. It contains 7 cervical vertebrae, muscles, nerves, blood vessels, lymphatic vessels, and glands (such as the thyroid gland). The neck is responsible for supporting the head, allowing its movement in various directions, and housing vital structures that enable functions like respiration and circulation.
Homeobox genes are a specific class of genes that play a crucial role in the development and regulation of an organism's body plan. They encode transcription factors, which are proteins that regulate the expression of other genes. The homeobox region within these genes contains a highly conserved sequence of about 180 base pairs that encodes a DNA-binding domain called the homeodomain. This domain is responsible for recognizing and binding to specific DNA sequences, thereby controlling the transcription of target genes.
Homeobox genes are particularly important during embryonic development, where they help establish the anterior-posterior axis and regulate the development of various organs and body segments. They also play a role in maintaining adult tissue homeostasis and have been implicated in certain diseases, including cancer. Mutations in homeobox genes can lead to developmental abnormalities and congenital disorders.
Some examples of homeobox gene families include HOX genes, PAX genes, and NKX genes, among others. These genes are highly conserved across species, indicating their fundamental role in the development and regulation of body plans throughout the animal kingdom.
"Bone" is the hard, dense connective tissue that makes up the skeleton of vertebrate animals. It provides support and protection for the body's internal organs, and serves as a attachment site for muscles, tendons, and ligaments. Bone is composed of cells called osteoblasts and osteoclasts, which are responsible for bone formation and resorption, respectively, and an extracellular matrix made up of collagen fibers and mineral crystals.
Bones can be classified into two main types: compact bone and spongy bone. Compact bone is dense and hard, and makes up the outer layer of all bones and the shafts of long bones. Spongy bone is less dense and contains large spaces, and makes up the ends of long bones and the interior of flat and irregular bones.
The human body has 206 bones in total. They can be further classified into five categories based on their shape: long bones, short bones, flat bones, irregular bones, and sesamoid bones.
A spinal fracture, also known as a vertebral compression fracture, is a break in one or more bones (vertebrae) of the spine. This type of fracture often occurs due to weakened bones caused by osteoporosis, but it can also result from trauma such as a car accident or a fall.
In a spinal fracture, the front part of the vertebra collapses, causing the height of the vertebra to decrease, while the back part of the vertebra remains intact. This results in a wedge-shaped deformity of the vertebra. Multiple fractures can lead to a hunched forward posture known as kyphosis or dowager's hump.
Spinal fractures can cause pain, numbness, tingling, or weakness in the back, legs, or arms, depending on the location and severity of the fracture. In some cases, spinal cord compression may occur, leading to more severe symptoms such as paralysis or loss of bladder and bowel control.
There is no medical definition for "dog diseases" as it is too broad a term. However, dogs can suffer from various health conditions and illnesses that are specific to their species or similar to those found in humans. Some common categories of dog diseases include:
1. Infectious Diseases: These are caused by viruses, bacteria, fungi, or parasites. Examples include distemper, parvovirus, kennel cough, Lyme disease, and heartworms.
2. Hereditary/Genetic Disorders: Some dogs may inherit certain genetic disorders from their parents. Examples include hip dysplasia, elbow dysplasia, progressive retinal atrophy (PRA), and degenerative myelopathy.
3. Age-Related Diseases: As dogs age, they become more susceptible to various health issues. Common age-related diseases in dogs include arthritis, dental disease, cancer, and cognitive dysfunction syndrome (CDS).
4. Nutritional Disorders: Malnutrition or improper feeding can lead to various health problems in dogs. Examples include obesity, malnutrition, and vitamin deficiencies.
5. Environmental Diseases: These are caused by exposure to environmental factors such as toxins, allergens, or extreme temperatures. Examples include heatstroke, frostbite, and toxicities from ingesting harmful substances.
6. Neurological Disorders: Dogs can suffer from various neurological conditions that affect their nervous system. Examples include epilepsy, intervertebral disc disease (IVDD), and vestibular disease.
7. Behavioral Disorders: Some dogs may develop behavioral issues due to various factors such as anxiety, fear, or aggression. Examples include separation anxiety, noise phobias, and resource guarding.
It's important to note that regular veterinary care, proper nutrition, exercise, and preventative measures can help reduce the risk of many dog diseases.
Scoliosis is a medical condition characterized by an abnormal lateral curvature of the spine, which most often occurs in the thoracic or lumbar regions. The curvature can be "C" or "S" shaped and may also include rotation of the vertebrae. Mild scoliosis doesn't typically cause problems, but severe cases can interfere with breathing and other bodily functions.
The exact cause of most scoliosis is unknown, but it may be related to genetic factors. It often develops in the pre-teen or teenage years, particularly in girls, and is more commonly found in individuals with certain neuromuscular disorders such as cerebral palsy and muscular dystrophy.
Treatment for scoliosis depends on the severity of the curve, its location, and the age and expected growth of the individual. Mild cases may only require regular monitoring to ensure the curve doesn't worsen. More severe cases may require bracing or surgery to correct the curvature and prevent it from getting worse.
Homeodomain proteins are a group of transcription factors that play crucial roles in the development and differentiation of cells in animals and plants. They are characterized by the presence of a highly conserved DNA-binding domain called the homeodomain, which is typically about 60 amino acids long. The homeodomain consists of three helices, with the third helix responsible for recognizing and binding to specific DNA sequences.
Homeodomain proteins are involved in regulating gene expression during embryonic development, tissue maintenance, and organismal growth. They can act as activators or repressors of transcription, depending on the context and the presence of cofactors. Mutations in homeodomain proteins have been associated with various human diseases, including cancer, congenital abnormalities, and neurological disorders.
Some examples of homeodomain proteins include PAX6, which is essential for eye development, HOX genes, which are involved in body patterning, and NANOG, which plays a role in maintaining pluripotency in stem cells.
The sacrum is a triangular-shaped bone in the lower portion of the human vertebral column, located between the lumbar spine and the coccyx (tailbone). It forms through the fusion of several vertebrae during fetal development. The sacrum's base articulates with the fifth lumbar vertebra, while its apex connects with the coccyx.
The sacrum plays an essential role in supporting the spine and transmitting weight from the upper body to the pelvis and lower limbs. It also serves as an attachment site for various muscles and ligaments. The sacral region is often a focus in medical and chiropractic treatments due to its importance in spinal stability, posture, and overall health.
Vertebroplasty is a medical procedure used to treat spinal fractures, particularly those resulting from osteoporosis or cancer. The procedure involves injecting a type of bone cement called polymethylmethacrylate (PMMA) into the damaged vertebra. This helps to stabilize the bone, reduce pain, and improve function.
During the procedure, a small incision is made in the skin, and a hollow needle is guided using fluoroscopy (a type of X-ray guidance) into the fractured vertebra. Once in place, the PMMA cement is injected into the bone, where it hardens quickly, providing stability to the fractured vertebra.
It's important to note that while vertebroplasty can be an effective treatment for some patients with spinal fractures, it's not always necessary or appropriate. The decision to undergo this procedure should be made in consultation with a healthcare provider and based on a thorough evaluation of the patient's individual needs and circumstances.
In medical terms, ribs are the long, curved bones that make up the ribcage in the human body. They articulate with the thoracic vertebrae posteriorly and connect to the sternum anteriorly via costal cartilages. There are 12 pairs of ribs in total, and they play a crucial role in protecting the lungs and heart, allowing room for expansion and contraction during breathing. Ribs also provide attachment points for various muscles involved in respiration and posture.
A compression fracture is a type of bone fracture that occurs when there is a collapse of a vertebra in the spine. This type of fracture is most commonly seen in the thoracic and lumbar regions of the spine. Compression fractures are often caused by weakened bones due to osteoporosis, but they can also result from trauma or tumors that weaken the bone.
In a compression fracture, the front part (anterior) of the vertebra collapses, while the back part (posterior) remains intact, causing the height of the vertebra to decrease. This can lead to pain, deformity, and decreased mobility. In severe cases, multiple compression fractures can result in a condition called kyphosis, which is an abnormal curvature of the spine that leads to a hunchback appearance.
Compression fractures are typically diagnosed through imaging tests such as X-rays, CT scans, or MRI scans. Treatment may include pain medication, bracing, physical therapy, or in some cases, surgery. Preventive measures such as maintaining a healthy diet, getting regular exercise, and taking medications to prevent or treat osteoporosis can help reduce the risk of compression fractures.
Medical Definition:
Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.
Spondylolysis is a defect or stress fracture in the pars interarticularis, which is a part of the vertebra in the lower back (lumbar spine). This condition most commonly affects young athletes who participate in sports that involve repetitive hyperextension of the lower back, such as gymnastics, football, and dance. Spondylolysis can cause lower back pain and stiffness, and if left untreated, it may lead to spondylolisthesis, a condition where one vertebra slips forward over the one below it. In some cases, spondylolysis may not cause any symptoms and may be discovered during an imaging test performed for another reason.
Kyphosis is a medical term used to describe an excessive curvature of the spine in the sagittal plane, leading to a rounded or humped back appearance. This condition often affects the thoracic region of the spine and can result from various factors such as age-related degenerative changes, congenital disorders, Scheuermann's disease, osteoporosis, or traumatic injuries. Mild kyphosis may not cause any significant symptoms; however, severe cases can lead to pain, respiratory difficulties, and decreased quality of life. Treatment options typically include physical therapy, bracing, and, in some cases, surgical intervention.
Polymethyl methacrylate (PMMA) is a type of synthetic resin that is widely used in the medical field due to its biocompatibility and versatility. It is a transparent, rigid, and lightweight material that can be easily molded into different shapes and forms. Here are some of the medical definitions of PMMA:
1. A biocompatible acrylic resin used in various medical applications such as bone cement, intraocular lenses, dental restorations, and drug delivery systems.
2. A type of synthetic material that is used as a bone cement to fix prosthetic joint replacements and vertebroplasty for the treatment of spinal fractures.
3. A transparent and shatter-resistant material used in the manufacture of medical devices such as intravenous (IV) fluid bags, dialyzer housings, and oxygenators.
4. A drug delivery system that can be used to administer drugs locally or systemically, such as intraocular sustained-release drug implants for the treatment of chronic eye diseases.
5. A component of dental restorations such as fillings, crowns, and bridges due to its excellent mechanical properties and esthetic qualities.
Overall, PMMA is a versatile and valuable material in the medical field, with numerous applications that take advantage of its unique properties.
"Sex factors" is a term used in medicine and epidemiology to refer to the differences in disease incidence, prevalence, or response to treatment that are observed between males and females. These differences can be attributed to biological differences such as genetics, hormones, and anatomy, as well as social and cultural factors related to gender.
For example, some conditions such as autoimmune diseases, depression, and osteoporosis are more common in women, while others such as cardiovascular disease and certain types of cancer are more prevalent in men. Additionally, sex differences have been observed in the effectiveness and side effects of various medications and treatments.
It is important to consider sex factors in medical research and clinical practice to ensure that patients receive appropriate and effective care.
Spinal curvatures refer to the normal or abnormal curvature patterns of the spine as viewed from the side. The human spine has four distinct curves that form an "S" shape when viewed from the side: cervical, thoracic, lumbar, and sacral. These natural curves provide strength, flexibility, and balance to the spine, allowing us to stand upright, maintain proper posture, and absorb shock during movement.
Abnormal spinal curvatures are often referred to as spinal deformities and can be classified into two main categories: hyperkyphosis (increased kyphosis) and hyperlordosis (increased lordosis). Examples of such conditions include:
1. Kyphosis: An excessive curvature in the thoracic or sacral regions, leading to a hunchback or rounded appearance. Mild kyphosis is common and usually not problematic, but severe cases can cause pain, breathing difficulties, and neurological issues.
2. Lordosis: An abnormal increase in the curvature of the lumbar or cervical spine, resulting in an exaggerated swayback posture. This can lead to lower back pain, muscle strain, and difficulty maintaining proper balance.
3. Scoliosis: A lateral (side-to-side) spinal curvature that causes the spine to twist and rotate, forming a C or S shape when viewed from behind. Most scoliosis cases are idiopathic (of unknown cause), but they can also be congenital (present at birth) or secondary to other medical conditions.
These abnormal spinal curvatures may require medical intervention, such as physical therapy, bracing, or surgery, depending on the severity and progression of the condition.
In the context of human anatomy, the term "tail" is not used to describe any part of the body. Humans are considered tailless primates, and there is no structure or feature that corresponds directly to the tails found in many other animals.
However, there are some medical terms related to the lower end of the spine that might be confused with a tail:
1. Coccyx (Tailbone): The coccyx is a small triangular bone at the very bottom of the spinal column, formed by the fusion of several rudimentary vertebrae. It's also known as the tailbone because it resembles the end of an animal's tail in its location and appearance.
2. Cauda Equina (Horse's Tail): The cauda equina is a bundle of nerve roots at the lower end of the spinal cord, just above the coccyx. It got its name because it looks like a horse's tail due to the numerous rootlets radiating from the conus medullaris (the tapering end of the spinal cord).
These two structures are not tails in the traditional sense but rather medical terms related to the lower end of the human spine.
The spinal canal is the bony, protective channel within the vertebral column that contains and houses the spinal cord. It extends from the foramen magnum at the base of the skull to the sacrum, where the spinal cord ends and forms the cauda equina. The spinal canal is formed by a series of vertebral bodies stacked on top of each other, intervertebral discs in between them, and the laminae and spinous processes that form the posterior elements of the vertebrae. The spinal canal provides protection to the spinal cord from external trauma and contains cerebrospinal fluid (CSF) that circulates around the cord, providing nutrients and cushioning. Any narrowing or compression of the spinal canal, known as spinal stenosis, can cause various neurological symptoms due to pressure on the spinal cord or nerve roots.
"Weight-bearing" is a term used in the medical field to describe the ability of a body part or limb to support the weight or pressure exerted upon it, typically while standing, walking, or performing other physical activities. In a clinical setting, healthcare professionals often use the term "weight-bearing exercise" to refer to physical activities that involve supporting one's own body weight, such as walking, jogging, or climbing stairs. These exercises can help improve bone density, muscle strength, and overall physical function, particularly in individuals with conditions affecting the bones, joints, or muscles.
In addition, "weight-bearing" is also used to describe the positioning of a body part during medical imaging studies, such as X-rays or MRIs. For example, a weight-bearing X-ray of the foot or ankle involves taking an image while the patient stands on the affected limb, allowing healthcare providers to assess any alignment or stability issues that may not be apparent in a non-weight-bearing position.
Biomechanics is the application of mechanical laws to living structures and systems, particularly in the field of medicine and healthcare. A biomechanical phenomenon refers to a observable event or occurrence that involves the interaction of biological tissues or systems with mechanical forces. These phenomena can be studied at various levels, from the molecular and cellular level to the tissue, organ, and whole-body level.
Examples of biomechanical phenomena include:
1. The way that bones and muscles work together to produce movement (known as joint kinematics).
2. The mechanical behavior of biological tissues such as bone, cartilage, tendons, and ligaments under various loads and stresses.
3. The response of cells and tissues to mechanical stimuli, such as the way that bone tissue adapts to changes in loading conditions (known as Wolff's law).
4. The biomechanics of injury and disease processes, such as the mechanisms of joint injury or the development of osteoarthritis.
5. The use of mechanical devices and interventions to treat medical conditions, such as orthopedic implants or assistive devices for mobility impairments.
Understanding biomechanical phenomena is essential for developing effective treatments and prevention strategies for a wide range of medical conditions, from musculoskeletal injuries to neurological disorders.
A cadaver is a deceased body that is used for medical research or education. In the field of medicine, cadavers are often used in anatomy lessons, surgical training, and other forms of medical research. The use of cadavers allows medical professionals to gain a deeper understanding of the human body and its various systems without causing harm to living subjects. Cadavers may be donated to medical schools or obtained through other means, such as through consent of the deceased or their next of kin. It is important to handle and treat cadavers with respect and dignity, as they were once living individuals who deserve to be treated with care even in death.
The lumbosacral region is the lower part of the back where the lumbar spine (five vertebrae in the lower back) connects with the sacrum (a triangular bone at the base of the spine). This region is subject to various conditions such as sprains, strains, herniated discs, and degenerative disorders that can cause pain and discomfort. It's also a common site for surgical intervention when non-surgical treatments fail to provide relief.
Bone cements are medical-grade materials used in orthopedic and trauma surgery to fill gaps between bone surfaces and implants, such as artificial joints or screws. They serve to mechanically stabilize the implant and provide a smooth, load-bearing surface. The two most common types of bone cement are:
1. Polymethylmethacrylate (PMMA) cement: This is a two-component system consisting of powdered PMMA and liquid methyl methacrylate monomer. When mixed together, they form a dough-like consistency that hardens upon exposure to air. PMMA cement has been widely used for decades in joint replacement surgeries, such as hip or knee replacements.
2. Calcium phosphate (CP) cement: This is a two-component system consisting of a powdered CP compound and an aqueous solution. When mixed together, they form a paste that hardens through a chemical reaction at body temperature. CP cement has lower mechanical strength compared to PMMA but demonstrates better biocompatibility, bioactivity, and the ability to resorb over time.
Both types of bone cements have advantages and disadvantages, and their use depends on the specific surgical indication and patient factors.
Orthopedic fixation devices are medical implants used in orthopedic surgery to provide stability and promote the healing of fractured or broken bones, as well as joints or spinal segments. These devices can be internal or external and include a variety of products such as:
1. Intramedullary nails: Long rods that are inserted into the center of a bone to stabilize fractures in long bones like the femur or tibia.
2. Plates and screws: Metal plates are attached to the surface of a bone with screws to hold the fragments together while they heal.
3. Screws: Used alone or in combination with other devices, they can be used to stabilize small fractures or to fix implants like total joint replacements.
4. Wires: Used to hold bone fragments together, often in conjunction with other devices.
5. External fixators: A external frame attached to the bones using pins or wires that is placed outside the skin to provide stability and alignment of fractured bones.
6. Spinal fixation devices: These include pedicle screws, rods, hooks, and plates used to stabilize spinal fractures or deformities.
7. Orthopedic staples: Small metal staples used to stabilize small bone fragments or for joint fusion.
The choice of orthopedic fixation device depends on the location and severity of the injury or condition being treated. The primary goal of these devices is to provide stability, promote healing, and restore function.
Kyphoplasty is a surgical procedure used to treat vertebral compression fractures, which are commonly caused by osteoporosis or cancer. The goal of kyphoplasty is to stabilize the fracture, reduce pain, and restore some or all of the lost vertebral body height.
During the procedure, a small incision is made in the back, and a narrow tube is inserted into the damaged vertebra under the guidance of fluoroscopy (a type of continuous X-ray imaging). A special balloon is then inflated inside the vertebral body to create a cavity or space. This process helps to restore the height of the vertebra and correct any abnormal kyphosis (hunchback) deformity that may have developed due to the fracture.
Once the desired cavity has been created, bone cement is injected into the space to stabilize the vertebra. The cement hardens quickly, providing immediate support and pain relief. After the procedure, patients are usually advised to limit their physical activity for a short period of time to allow the cement to fully set.
It's important to note that kyphoplasty is not suitable for all types of spinal fractures or conditions, and its effectiveness may vary depending on the individual case. Therefore, a thorough evaluation by a spine specialist is necessary before deciding whether this procedure is appropriate.
Compressive strength is a measure of the maximum compressive load that a material or structure can withstand before failure or deformation. It is typically expressed in units of pressure, such as pounds per square inch (psi) or megapascals (MPa). Compressive strength is an important property in the design and analysis of structures and materials, as it helps to ensure their safety and durability under compressive loads.
In medical terminology, compressive strength may refer to the ability of biological tissues, such as bone or cartilage, to withstand compressive forces without deforming or failing. For example, osteoporosis is a condition characterized by reduced bone density and compressive strength, which can increase the risk of fractures in affected individuals. Similarly, degenerative changes in articular cartilage can lead to decreased compressive strength and joint pain or stiffness.
Bone density refers to the amount of bone mineral content (usually measured in grams) in a given volume of bone (usually measured in cubic centimeters). It is often used as an indicator of bone strength and fracture risk. Bone density is typically measured using dual-energy X-ray absorptiometry (DXA) scans, which provide a T-score that compares the patient's bone density to that of a young adult reference population. A T-score of -1 or above is considered normal, while a T-score between -1 and -2.5 indicates osteopenia (low bone mass), and a T-score below -2.5 indicates osteoporosis (porous bones). Regular exercise, adequate calcium and vitamin D intake, and medication (if necessary) can help maintain or improve bone density and prevent fractures.
Tuberculosis (TB) of the spine, also known as Pott's disease, is a specific form of extrapulmonary tuberculosis that involves the vertebral column. It is caused by the Mycobacterium tuberculosis bacterium, which primarily affects the lungs but can spread through the bloodstream to other parts of the body, including the spine.
In Pott's disease, the infection leads to the destruction of the spongy bone (vertebral body) and the intervertebral disc space, resulting in vertebral collapse, kyphosis (hunchback deformity), and potential neurological complications due to spinal cord compression. Common symptoms include back pain, stiffness, fever, night sweats, and weight loss. Early diagnosis and treatment with a multidrug antibiotic regimen are crucial to prevent long-term disability and further spread of the infection.
Osteoporosis is a systemic skeletal disease characterized by low bone mass, deterioration of bone tissue, and disruption of bone architecture, leading to increased risk of fractures, particularly in the spine, wrist, and hip. It mainly affects older people, especially postmenopausal women, due to hormonal changes that reduce bone density. Osteoporosis can also be caused by certain medications, medical conditions, or lifestyle factors such as smoking, alcohol abuse, and a lack of calcium and vitamin D in the diet. The diagnosis is often made using bone mineral density testing, and treatment may include medication to slow bone loss, promote bone formation, and prevent fractures.